A number of patients today undergo recurring medical procedures requiring repeated skin penetrating access to the patient's internal hollow organs, including organs contained within the mediastinal, chest, abdominal and peritoneal cavities, and organs forming the patient's circulatory system, i.e., blood vessels. One such recurring medical procedure is hemodialysis. Currently, over one million patients worldwide suffer from End State Renal Disease (ESRD) conditions and require some form of daily or thrice weekly dialysis treatment via needle or catheter access. Peritoneal Dialysis is one form of dialysis treatment requiring needle or catheter access whereby fluids placed into the peritoneal cavity via a temporary or permanently placed access catheter provide osmotic transfer of blood containing toxins into solutions pumped into and removed from within the peritoneal organ cavity. A second form of dialysis treatment is a direct blood filtering process, whereby a needle or catheter is placed directly into a vein or artery, and through a series of connecting tubing, blood is removed and re-circulated back into the patient after filtration of the blood. These two hemodialysis procedures are the most common means for metabolic toxin removal from body fluids when a patient experiences total or bilateral renal failure.
Without needle or indwelling catheter organ access for dialysis, there is no physical connection means to conduct dialysis toxin removal, and the ESRD patients would die within days of total renal failure. Hence, the insertion method and form of dialysis connection access relates directly to the patient's ability to have body fluids contained within an internal organ communicate and be safely connected “externally outside the body” for the purposes of blood hemofiltration.
Because both types of dialysis treatment techniques discuss above require trained medical personnel for needle or catheter access and the administration of the actual external dialysis filtration process, there are significant healthcare hazards for both the patient and healthcare worker associated with such traditional needle access methods. Most ESRD patients must be transported to a public dialysis treatment center for treatment.
Some form of needle or indwelling catheter organ access is required as a physical connection means to conduct dialysis toxin removal. The insertion method employed and the form of dialysis access used affects the patient's ability to have body fluids contained within an internal organ communicate and be safely connected externally outside the body for the purpose of blood hemofiltration.
Most ESRD patients must travel to a public dialysis treatment center for treatment. Financial and logistical considerations are current sources of difficulty for an ESRD patient in obtaining necessary dialysis treatments. Consequently, any young or new ESRD patient must be placed into a treatment lottery, and may end up having to go for dialysis treatments at inconvenient hours (e.g., 2:00 AM to 6:00 AM). In addition, many patients are only being treated for a maximum of 3–4 hours per visit, and only 3 times per week.
Recent published studies have shown that “daily dialysis” treatment techniques bring many of these ESRD patient's blood toxicity levels down to normal, non-toxic levels. Thus, dialysis treatment approaching 3–4 hours per visit, three times per week, is inadequate for lowering patient toxicity levels to normal levels. Other studies have concluded that more frequent dialysis improves patient health and well-being, enabling patients to be more productive and lead a more independent life, while reducing reliance on medications and hours spent in the hospital. Reduction of time spent in hospitals helps the healthcare industry in that patient populations are growing at approximately 6%–7% annually, which could lead to a burden on our health care facilities.
Without a kidney transplant, the average life span of even the healthiest patient who has experienced total renal failure, is only about 5 years. It is now known from published clinical studies that when a patient can be treated “daily” with dialysis, even with shorter, less efficient periods of time on the dialysis machine, those individuals' blood toxicity levels return to near normal, and remain almost equivalent to their prior functional kidney performance levels. Often, the patients receiving daily dialysis no longer require the expense of erythropoietin-type medications to help stabilize their red blood cells during periods of blood toxicity. Erythropoietin is a significant cost to the patients, and it is required for dialysis patients who need to extend the survival half-life of their oxygen carrying red blood cells, especially under extreme blood toxicity conditions. Current indications are that more cost-effective daily dialysis will extend the survival rate of ESRD patients from a projected life expectancy of 5 years with 3–4 treatments per week, to about 20 years or more.
One of the common denominators relating to treatment cost with the ESRD patients is the need for a trained healthcare worker to clean, prepare, and install a needle, guide wire, or catheter into the body fluid organ access site for external connection of the dialysis tubing sets to the dialysis machine. Most dialysis patients require insertion of two large gauge dialysis needles directly through the skin and precisely into the body fluid organ, surgically installed graft, vein, or artery. Such a requirement means that for a patient to undergo dialysis treatment, they must travel to a center for a professionally trained healthcare worker to find the correct subcutaneous blood vessel location and then insert the access device needle or catheter precisely into the blood containing organ, without significantly damaging either the internal or external vessel wall surface. Without precision needle or catheter placement, a patient can bleed to death from a poorly placed needle or catheter. Other possible complications include total occlusion of the vessel, graft, or connection setup, requiring total access device removal and reinstallation elsewhere. Another common complication from needle or catheter access is the formation of a massive subcutaneous hematoma, which can become infected. The hematoma can require surgical intervention to drain, de-clot and repair, and sometimes results in death due to their already toxic blood conditions and compromised autoimmune protection system.
There are a number of complicating issues relating to the process of repeatedly sticking and cannulating a patient's circulatory organ system and removing/returning blood back to the patient. One significant complication is the need for maintenance of a sterile installation and connection technique for all components involved in establishing dialysis access through the patient's skin and into the hollow targeted organ, as well as connection to the dialysis tubing set, filter, and dialysis pump apparatus. Another complication is the inability of a particular artery or vein to be repeatedly cannulated or punctured at substantially the same convenient needle or catheter access site, due to vessel trauma, exit wound inflammation, dialysis graft complications, and/or enlarged needle hole formation resulting in massive needle hole bleeding/ hematoma formation. Repeated dialysis needle punctures create unwanted scar tissue formation and infection. Both conditions are directly related to repetitive needle and catheter cannulation through the skin. Such large gauge needle cannulation complications are uncomfortable for the patient and the healthcare worker, due to the associated pain of additional needle sticks. Infection complications of these needle access sites are difficult to treat, because of the constant migratory effects of nosocomial infections, which have been well documented to routinely originate from direct contact with topical skin sourced Staphylococcocus bacteria. These frequently occurring needle access complications often require surgical intervention to repair, reconstruct, or remove the affected vessel organ, in addition to requiring extended hospital admission and costly medication treatment with IV medications.
One approach to help solve some of these needle and indwelling catheter access complications, can be found in PCT Patent Application No. WO 99/20338 (“the '338 application”). The device of the '338 application is described as being an implantable metal port housing which is surgically installed within the body of a patient. The device includes a main body having two openings for connecting the implanted housing to blood vessels under the skin and or under the dermal layer of the patient. Implantation of the device requires a large surgical incision in the skin, separation or removal of a portion of the skin, insertion of the metal alloy housing or port can, attachment of the blood vessels to the implanted housing, and subsequent healing of the skin wound around the entire perimeter of the main housing body. The main housing body and blood vessel connecting portions of this device reside entirely below the dermal skin surface.
The device described in the '338 application has a main housing body and blood vessel connection means radiating from this housing that are positioned below the dermal skin layer, and may be subject to significant amounts of skin trauma, disruption, and inflammation surrounding the implanted device.
The main body of the device of the '338 application requires a flat or planar sealing surface to which a flat planar protective body lid or connecting member lid member seals. The lid then mounts to the housing via linear holding elements that press down onto and deflect holding means on the protective body to establish a sealable surface with the main housing sealing surface. The lid holding means are described as being sideways-directed linear flanges to cooperate with holding elements on the main body. The '338 application further states that the holding elements must be deflected to function. The holding elements, as described, push down and deflect the linear flanges to keep tension on the flat and planar protective body lid to maintain a sealable surface. This holding element and the holding means are the only described mechanisms for maintaining a sealable surface to the main housing's flat and planar sealing surface. To change a lid, an attachable linear slide holder, tool, or cassette, fits over an exposed portion of the indwelling main body outer surface and protruding holding elements to allow the simultaneous change-out of the protective body lid as it is guided by the straight planar holding elements located on top of the exposed outer surface of the main body housing. The protective body lid is displaced in a one-way linear push fashion by another connecting member lid with identical holding means using mechanical lever assistance in the holder, tool, or cassette device. The linear slide tool with mechanical lever assistance for protective lid replacement or exchange is then removed from the main body with the used protective lid held onto the skin contacting surface of the linear slide tool for their combined disposal.
As a large indwelling implant, the access port design of the '338 device has no means for remote incision placement for the blood vessel attachment legs or connection means. The device housing and blood vessel connection legs must sit directly on top of, or within, the surgically exposed sub-dermal tissue location. Installation connection of an outwardly directed tube connection means of the '338 device requires blunt dissection into the sub-dermal tissue directly under, or to, the immediate side area of the installed main housing body, clearly below the surface of the skin. The main housing body of the '338 device after surgical installation may also be sensitive to touch and/or be painful to topical depression or compression by the patient, due to direct main housing body contact with subdermal tissue, and the potential for chronic inflammation in, under, and around the neighboring tissue following implantation. Such compromising issues may be further exasperated by poor wound tissue healing at both the housing/dermal skin contact zone, and/or the tissue contact zone directly under the implanted metal port can, as there is no disclosure of providing a microporous healable cuff material for tissue incorporation. With such large non-porous metal surfaces, there is little or no biological attachment of healing tissue to help stabilize movement of the main body of the '338 device. Without healthy remodeled collagen producing tissue growth to help stabilize the housing of the '338 device, tissue will remain swollen and inflamed. Due to the potential size requirements to fabricate a flat and planar sealable surface mechanism, the risk of dermal compression about the perimeter of the indwelling metal device could lead to necrosis of the surrounding tissue, which can only be treated by surgical removal, followed by skin graft reimplantation to replace the lost dermal skin over the effected area.
In the presence of any implanted device or sub-dermal wound infection, aggressive medical treatment for adjacent contacting tissues about the indwelling structure requires lengthy treatment periods with powerful intravenous or intramuscular injectable antibiotics, and/or complete surgical removal of the implant. Failure to diagnose and treat device-related infections could easily lead to tissue necrosis in, under, and around the implanted main body housing. Even if there were no visible or apparent physical signs of device infection, substantial sub-dermal inflammation in and around, and directly under the main housing of the '338 device would over time likely result in subsequent infection, principally due to the massive amount of tissue healing and collagen tissue remodeling required to stabilize the non-cell porous implantable structure. Historically, published studies on similar implantable metal port structures indicate that recurring infection and chronic inflammation can also lead to other life threatening conditions and systemic blood problems, such as endocarditis, bacteremia/septicemia, and/or hypercoagulation and thrombosis.
Another known device is described in U.S. Pat. No. 5,474,526. A substantial portion of the main housing of this device disclosed in the '526 patent is again implanted completely within the body of the patient with the exception of an outer rim portion of the main implanted body housing extending outward through the skin. The '526 device has many of the same device requirements as the '338 device. An outward coupling means achieves a connection to the housing by rotation of a stop-cock like connecting member relative to the housing after axial insertion to one exposed open end of the indwelling the housing. A coupling means makes the connection between the artery and vein of the patient and the external apparatus, such as a dialysis machine. The implanted device is substantially indwelling to the skin and connected to the blood vessels by port members which radiate from the main body housing below the surface of the skin, which essentially results in a totally subcutaneously implanted device. In similar fashion to the '338 device, the '526 device is likely to experience significant displacement of skin and dermal tissue. The same concerns for infection are likely to occur with this same non-porous metal housing construction, with bacterial colonization spreading from one surface plane of the '526 main body housing within the large installation incision to another indwelling surface plane, followed by inflammation of the localized tissue around and under the implantable metal housing. Neither the '338 patent, nor the '526 patent, teach or suggest provisions for limiting the amount of implantable material surface area for reduced surgical installation tissue dissection, or tissue disruption. Further, neither the '338 patent device, nor the '526 patent device descriptions provide design elements or surgical installation considerations for encouraging remote wound incisions to help improved healing after implantation or help control or minimize main body housing infection with such port devices. Additionally, neither patent describes material specifications for maximizing tissue attachment to the implanted main body housing for well-anchored, collagen remodeling dermal tissue.